1. Field of the Invention
The present invention relates to a segmented photomultiplier tube having at least two multiplication paths, including a sealed envelope having a front face on the inner surface of which a photocathode is provided, and from the latter, arranged one after the other, an electronic optical member providing a division of the photo-electrons in one of the multiplication paths according to their starting position from the photo-cathode, as well as an electron multiplier of the segmented type, having at least one input dynode.
2. Description of the Related Art
A photomultiplier of this type is disclosed in the document EP-A-428 215. This document has more specifically for its object a class of photomultipliers for which the number of paths is not so high and which are of a simple and cheap construction. A major application of this type of photomultipliers is the use as a contiguous mosaic arrangement for determining the positions in space of localized luminous radiation. In the majority of cases these radiations have their origin in scintillators placed in front of each tube. As far as the realization of a segmented photomultiplier (i.e. multi-way) tube remains rather cheap, it can be more economical to use this type of photomultipliers in such applications instead of conventional tubes. Moreover, if the basic photomultipliers of a segmented tube are small, the luminous event can be located with greater precision, provided the segmented tubes used have performances which are as uniform as possible from one tube to the other and from one path to the other. A further point to be taken into account consists in minimizing to the highest possible extent the diaphoty 1 between the paths of one and the same tube.
The segmented tube disclosed in the above-mentioned document, satisfies to a certain extent the structural simplicity looked for because it effects the distribution of the electrons over the different paths according to their starting position from the photo-cathode by means of an electronic optical means whose essential components are common to all the paths.